Fahrin's Chemistry Honors Blog

Thursday, April 7, 2011

To fully understand what exactly happened in Chernobyl and Japan we first need to understand how Nuclear Reactors work.A Nuclear Reactor is a system that contains and manages the sustained nuclear chain reactions (1). A nuclear reactor works by fuel and is made up of heavy atoms that divide when they absorb neutron. Then, it is placed into the reactor vessel along with a little neutron source. The neutron begins a chain reaction where every atom that divides releases more neutrons that cause other atoms to split. Each time an atom divides, it releases big amounts of energy in the form of heat. The heat is carried out of the reactor by coolant, and this coolant is generally water. Then the water heats up and goes off to a turbine to spin a generator.--------------------To further understand what happened in Chernobyl and In Japan we have to know a few terms that have to do with a Nuclear Reactor/Reaction. * Core: The core is part of the reactor that contains the nuclear fuel to generate most of the heat. * Coolant: The coolant is the material that goes through the core. Its job is to transfer the heat from the fuel to the turbine. * Turbine: The turbine converts heat from the coolant to electricity. * Containment: The containment is the structure that splits the reactor from the environment. * Cooling Towers: Cooling towers dispose the excess heat that are not able to convert into energy. -------------------This is an Image of How a Nuclear Reactor System WorksPicture From: http://www.whatisnuclear.com/articles/nucreactor.html------------------What Happened at Chernobyl? On April 26, 1986 the worst disaster in nuclear history occurred in the station at Chernobyl, Ukraine. It is described as “one of the most frightening environmental disasters in the world (2). Chernobyl was a little known town in north central Ukraine on the Pripyiat River near the Belarus border. The failure of the system was caused by the attempt of technicians to install a security system and reactor number 4 caused much of the damage. The nuclear plant was made up of four graphite reactors. The world first learned of this accident from Sweden because the “radiation was detected at Swedish monitoring stations”. The operators of the fourth unit were trying to do a controlled experiment by gradually allowing power into the reactor and the reactor was supposed to fall to low levels but it didn’t. The aim of the test was to monitor the dynamics of the graphite reactor with limited power flow. Twelve hours after power reduction was started the power had reached to 50 percent. Since only one turbine was needed to take in the decreased amount of steam plant 2 was turned off. Then the power had been reduced to 30 percent. During this time one of the operators had made a huge mistake. Instead of keeping power at 30 percent, the operator had forgotten to reset a controller, which caused the power to fall to 1 percent. Water had started to fill at the core, and xenon was building up in the reactor and the power was too low for the test. Then the operator’s added water to the reactor is and the reactor is heated by the nuclear reaction. The operator boosted the reactor to 7% by removing all but 6 of the control rods. Not only was this a violation of procedure but also the reactor was not constructed to operate at such low power. The operator failed to get the flow of water corrected and the reactor was continuing to be unstable. To avoid aborting the controlled experiment the operator disabled emergency shutdown procedures. By 01:22 am, when the operators thought they had the most stable conditions, they decided to start the test (3). The operator blocked automatic shutdown on low water level and the loss of both turbines because of a fear that a shutdown would abort the test and they would have to repeat tests. As soon as the test began the other turbines were shut down and the power in the reactor started to slowly increase because of the lessening in water flow caused by the turbine shutdown. The operator tried to initiate manual shut down but that lead to a fast power increase. In no time did the reactor reach 120 times its full power and all the radioactive fuel disintegrated and due to all the pressure the entire top shield of the reactor blew up. Then experts tried to throw radioactive material out into the atmosphere for 10 or more days. Also, multiple fires broke out on both inside and outside of the reactor plant. By 5:00 pm that same day the firemen had suffocated the flames. In the later days to come, about 5000 tons of materials were thrown into the reactor to extinguish burning graphite and to smother radiation release. To date, there is no evidence if the dumping of these materials actually achieved their goal. Recent data has shown only a fraction amount of these materials actually got into the well. Picture From: http://www.google.com/imgres?imgurl=http://www.treehugger.com/chernobyl-nuclear-reactor-photo346.jpg&imgrefurl=http://www.treehugger.com/files/2009/03/chernobyl-radiation-nuclear-explosion-harming-animals.php&usg=__umT1Clfsk6z4gSz57ynzGXSctlE=&h=381&w=468&sz=59&hl=en&start=0&sig2=eo42SjmngkmrgkTvX18GlA&zoom=1&tbnid=jVBDZFCpWgTFmM:&tbnh=113&tbnw=148&ei=f3eeTanHH4m60QGbzLydBQ&prev=/images%3Fq%3DChernobyl%2Bnuclear%2Bdisaster%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DX%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=402&vpy=115&dur=742&hovh=203&hovw=249&tx=148&ty=107&oei=f3eeTanHH4m60QGbzLydBQ&page=1&ndsp=23&ved=1t:429,r:2,s:0How did this affect the people of Chernobyl? Due to this catastrophic accident, the people of Chernobyl were exposed to radiation “two times bigger than that created by the bombs dropped on Hiroshima and Nagasaki during World War Second”. 70 percent of the radiation is estimated to have fallen on Belarus and still 10 years later babies are being born with no arms, no eyes, no legs, only stumps for limbs and suffer from various other diseases. It is estimated that over 15 million people have been victimized by the disaster. It has also been estimated that eventually the accident will have more victims than World War II and it will cost over 60 Billion dollars to make these people healthy/normal. Approximately thirty-one lives were lost on the spot and approximately more than 600,000 people were involved with the aftermath. Hundreds of thousands of Ukrainians, Russians, and Belorussians had to abandon entire cities and settlements within the thirty-kilometer zone of extreme contamination (4). A lot of money has been spent and will continue to be spent to relocate neighborhoods and decontaminate the once rich farmlands. What did the Soviet Union do to fix the problem? The Soviet Union has designed several plans to cover the damaged reactors. The officials decided to close off the Chernobyl reactors with walls. After, the installation of the heavy steel and concrete walls, the protective walls were about 28 stories high and a steel roof was also added on. Despite all these efforts to keep people safe the sarcophagus is cracked and is slowly being demolished. Multiple sensors were placed to monitor levels of gamma radiation, neutron flux, temperature, heat flux, as well as the concentrations of hydrogen, carbon monoxide and water vapor in the air but much damage has already been done and it is too late to fix anything. -------------------What Happened in Japan?~In Japan, they had three reactors that exploded these reactors were reactors 1, 2, and 3. In these reactors the water was heated and later exposed rods. The exposure to the rods naturally caused the rods to overheat. Since there was no water to act as a coolant it caused the reactor to explode. Japan has tried to do many this to calm the reactors down. Since Japan is located near the water the have tried to get ocean water to act as a coolant to regulate the temperatures. Picture From: http://www.google.com/imgres?imgurl=http://androidspin.com/wp-content/uploads/2011/03/Japan-Tsunami.jpg&imgrefurl=http://androidspin.com/2011/03/14/att-and-verizon-offer-free-texts-and-calls-to-japan/&usg=__8iaUW7lpTeXdOpzEt6Ic5WUnu2g=&h=373&w=398&sz=31&hl=en&start=0&sig2=suzU2gHtD5pj_PAwAOIcsA&zoom=1&tbnid=iL39aOdjJxe0oM:&tbnh=113&tbnw=122&ei=JHieTdhAjbi2B7GN1YAD&prev=/images%3Fq%3DJapan%2527s%2Brecent%2Btsunami%2Bpictures%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=111&vpy=121&dur=416&hovh=217&hovw=232&tx=155&ty=119&oei=DHieTZD0PKKV0QGHnoCIBQ&page=1&ndsp=21&ved=1t:429,r:0,s:0Picture From: http://www.google.com/imgres?imgurl=http://www.indiatalkies.com/images/nuclear-reactors41782R.jpg&imgrefurl=http://www.indiatalkies.com/2011/03/water-sprayed-japan-nuclear-reactors.html&usg=__tssLdtT1V84XYO6Mxhsf6Jyi1DI=&h=520&w=539&sz=85&hl=en&start=0&sig2=IiqxRIbXnhmuJtK6Um0yWg&zoom=1&tbnid=PEwQq18VDYJ_cM:&tbnh=117&tbnw=120&ei=yHieTayAKMK4twePiomPAw&prev=/images%3Fq%3Djapan%2527s%2Bnuclear%2Breactors%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch0%2C173&um=1&itbs=1&iact=rc&dur=424&oei=o3ieTaTEIqLz0gH06YSABQ&page=1&ndsp=22&ved=1t:429,r:21,s:0&tx=98&ty=44&biw=1298&bih=553-------------------Similarities between Japan and Chernobyl.-Although Chernobyl's nuclear disaster was far more hazardous Japan and Chernobyl do share some similarities. ~ Japan assisted their citizens a lot more than Chernobyl did but evacuation was held in both places~ Even though Japan is not as affected as Japan radiation was spread in both areas to the environments that surrounded the reactors-------------------What were the Differences between Japan and Chernobyl? There are many differences because Japan's nuclear reactor even wasn't as bad as Chernobyl's.~The designs of the reactors were different in both Japan and Chernobyl.Physicist Alexander Sich said construction, both outside and inside the reactor, is fundamentally different (5). Chernobyl used graphite in their moderator. Japan used water in their moderator. Chernobyl therefore received a greater impact because graphite can very easily cause fires and explosions. ~Japan's reactors had a sturdy and heavy steel and concrete wall to protect the environment. Chernobyl did not have any sort of wall or containment around their reactor and there it caused the radiation in the environment to be deadly.~Chernobyl's disaster was caused due to a controlled experiment. The event was solely caused by human error. Japan's disaster was caused by a natural disaster the tsunami and earthquake.~Chernobyl's reactor' released much more radiation than Japans reactors. Picture From: http://news.nationalgeographic.com/news/energy/2011/03/1103165-japan-nuclear-chernobyl-three-mile-island/The control room at Chernobyl's Reactor No. 4 is shown here. Reactor design, wind patterns, communication and other factors can cause differences in the severity of nuclear accidents (6).--------------------Should we be Concerned? Yes, we should be concerned for the people dealing with these issues and should try to help them as best as we can but we should not be concerned with radiation issues in the the United states because Japan's radiation will not come around the U.S. Also, the people in Japan will not suffer as badly as the people in Chernobyl did because Japan had built a better reactor than the Soviets did. ----------------------------------------------------------------Sources1. http://www.whatisnuclear.com/articles/nucreactor.html2. http://oii.org/html/story.html3. http://library.thinkquest.org/3426/4. http://www.ibiblio.org/expo/soviet.exhibit/chernobyl.html5. http://www.post-gazette.com/pg/11075/1132513-115.stm6. http://news.nationalgeographic.com/news/energy/2011/03/1103165-japan-nuclear-chernobyl-three-mile-island/7. http://www.google.com/imgres?imgurl=http://androidspin.com/wp-content/uploads/2011/03/Japan-Tsunami.jpg&imgrefurl=http://androidspin.com/2011/03/14/att-and-verizon-offer-free-texts-and-calls-to-japan/&usg=__8iaUW7lpTeXdOpzEt6Ic5WUnu2g=&h=373&w=398&sz=31&hl=en&start=0&sig2=suzU2gHtD5pj_PAwAOIcsA&zoom=1&tbnid=iL39aOdjJxe0oM:&tbnh=113&tbnw=122&ei=JHieTdhAjbi2B7GN1YAD&prev=/images%3Fq%3DJapan%2527s%2Brecent%2Btsunami%2Bpictures%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=111&vpy=121&dur=416&hovh=217&hovw=232&tx=155&ty=119&oei=DHieTZD0PKKV0QGHnoCIBQ&page=1&ndsp=21&ved=1t:429,r:0,s:08. http://www.google.com/imgres?imgurl=http://www.treehugger.com/chernobyl-nuclear-reactor-photo346.jpg&imgrefurl=http://www.treehugger.com/files/2009/03/chernobyl-radiation-nuclear-explosion-harming-animals.php&usg=__umT1Clfsk6z4gSz57ynzGXSctlE=&h=381&w=468&sz=59&hl=en&start=0&sig2=eo42SjmngkmrgkTvX18GlA&zoom=1&tbnid=jVBDZFCpWgTFmM:&tbnh=113&tbnw=148&ei=f3eeTanHH4m60QGbzLydBQ&prev=/images%3Fq%3DChernobyl%2Bnuclear%2Bdisaster%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DX%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=402&vpy=115&dur=742&hovh=203&hovw=249&tx=148&ty=107&oei=f3eeTanHH4m60QGbzLydBQ&page=1&ndsp=23&ved=1t:429,r:2,s:09. http://www.google.com/imgres?imgurl=http://www.indiatalkies.com/images/nuclear-reactors41782R.jpg&imgrefurl=http://www.indiatalkies.com/2011/03/water-sprayed-japan-nuclear-reactors.html&usg=__tssLdtT1V84XYO6Mxhsf6Jyi1DI=&h=520&w=539&sz=85&hl=en&start=0&sig2=IiqxRIbXnhmuJtK6Um0yWg&zoom=1&tbnid=PEwQq18VDYJ_cM:&tbnh=117&tbnw=120&ei=yHieTayAKMK4twePiomPAw&prev=/images%3Fq%3Djapan%2527s%2Bnuclear%2Breactors%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1298%26bih%3D553%26tbm%3Disch0%2C173&um=1&itbs=1&iact=rc&dur=424&oei=o3ieTaTEIqLz0gH06YSABQ&page=1&ndsp=22&ved=1t:429,r:21,s:0&tx=98&ty=44&biw=1298&bih=553

Friday, November 12, 2010

OBSERVATIONS: Rutherford's Gold Foil Experiment-Focused a beam of positively charged particles (alpha particles) on a thin sheet of gold foil and set up a ring of detectors around the foil*It was thought that the positively charged alpha particles would pass through atoms with very little deflection because the positive charges were thought to be spread out evenly. Rutherford and his colleagues were shocked to see:-A few alpha particles had very large deflections or bounced straight back towards the source-They concluded that the alpha particles going straight through were passing through nearly empty space and that the particles bouncing back were hitting dense, positively charged centers.

Wednesday, October 6, 2010

Thomson started the Cathode Ray experiment in the 1894 (19th century) at the Cavendish Laboratory at Cambridge University. He experimented with currents of electricity inside empty glass tubes.

THOMSON’S FIRST CATHODE RAY EXPERIMENT

Thomson’s first experiment was to investigate whether or not the negative charge could be separated from the cathode rays by magnetism.

To observe this he built a cathode ray tube with a metal cylinder on the end. This cylinder had two slits in it, leading to electrometers, which could measure small electric charges.

Thomson found that if the rays were magnetically bent and they could not enter the slit. Therefore, the electrometer registered little charge.

Thomson concluded that the negative charge was inseparable from the rays.

He found his conclusion by applying a magnetic field across the tube. Since the electrometers recorded no activity and so the charge had been bent away by the magnet.

THOMSON’S SECOND CATHODE RAY EXPERIMENT

Thomson’s second experiment was to prove that the rays carried a negative charge. His previous experiments did not prove this but he wanted to keep trying because he believed his previous experiment had been flawed because of the traced amounts of gas and a bad vacuum.

Thomson made a cathode ray with an almost perfect vacuum. This vacuum had two electrical pates halfway down the tube, one positively charged and one negatively charged. He knew that electrical charges repelled on another, which allowed him to see whether the charge was a positive or negative. He would observe this by looking at the light deflection pattern of the cathode ray

The rays were deflected by the electric charge. He concluded that cathode rays had a negative charge.

THOMSON’S THIRD EXPERIMENT-1896

Although Thomson had performed all these experiments he was still curious to know what was the size of the cathode rays.

Thomson used a charge-to-mass ratio because he knew the weight of the cathode ray tube, the heat, the electrical current, and how much heat had been added from the electrons firing.

He concluded that the negative cathode ray particles were a thousand times tinier than an atom.

Along these lines he proved the existence of subatomic particles.

PROPOSAL

Since these puzzling rays of particles were a lot smaller than atoms Thomson concluded that they were microscopic pieces of atoms.

"He called these particles "corpuscles," and suggested that they might make up all of the matter in atoms. The “corpuscles” atoms were divisible."^1 (supposed to be a footnote- “J.J Thomson’s Cathode Ray Experiment.” Experiment-Resources.com. n.d. Web. 3 Oct. 2010.)

Thomson imagined the atom as being made up of these corpuscles swarming in an area of positive charge. This was his plum pudding model. Ernest Rutherford later proved this model incorrect.

IMPORTANCE

The significance of the mass-to-charge ratio is that two particles with the same mass-to-charge ratio travel in the same pathway in a vacuum when focused on the constant electric and magnetic fields.

Sunday, September 12, 2010

For this experiment I used a peppermint because it is a candy people often like to use to freshen up their breath. I observed what would happen to peppermints after I put it lemon juice, vinegar, and clorox (tide laundry detergent), clorox (disinfecting), and boiling water. This process allowed me to observe some physical properties of a peppermint and some chemical properties too. _______________________________________________________________________________________Physical Properties: Color: Red and White StripesSmell: PeppermintTexture: SmoothDiameter: 1/2 inchLength: Little larger than 3/4 inch _______________________________________________________________________________________Observing Chemical Properties by Performing a Chemical Reaction

Lemon Juice

For this experiment, I first poured a little bit of lemon juice into a glass and then dropped a peppermint into it. I then stirred it a little bit and watched what would happen. 1. When a peppermint is added to lemon juice, it immediately started to fizz because it was dissolving the peppermint. 2. I then observed a color change in the lemon juice. It changed colors from a yellow-ish to a red-ish & pink-ish color. 3. After the peppermint half-way dissolved i noticed that there was a slight change in odor, the odor of the lemon juice started to smell more lemony that it initially smelled5. The glass now has the lemon juice with the dissolved peppermint and bubbles on top.6. It looked like the lemon juice got more dense (thicker) than it was before. 7. It also looked like the peppermint sediments and lemon juice were slowly starting to separate I saw sediments starting to go to the bottom of the glass and the lemon juice was rising to the top. I think this happened because the peppermint sediments were more dense than the lemon juice therefore causing it to settle at the bottom of the glass. -------------Conclusion: I had figured out a chemical reaction was occurring because of color change, odor change, a solid was formed, and the bubbles of gas were produced. I also think the volume changed because the glass seemed to have more inside of it.

Vinegar

I first took a glass and poured some vinegar in it. I then took the peppermint and dropped it into the glass. 1. As soon as the peppermint was dropped into the vinegar the vinegar started to fizz.2. It started to dissolve right after it was dropped into the vinegar. 3. Gradually changed color from clear to pale pink-orange color as it dissolved.3. Fizzing was happening until the peppermint was not completely dissolved. --------------Conclusion: I had known a chemical reaction had taken place after I saw the color change, odor change, and saw the bubbles of gas were being produced.

Clorox (Tide Laundry Detergent)

I first took a glass and poured the clorox into the glass and then dropped the peppermint into the glass.1. The color changed from a blue to a purple-blue color.2. The clorox smelled more pepperminty.3. The red stripes on the peppermint went to the bottom of the glass. On the bottom of the glass there was a redish color and on the top of the glass there was the blue-ish-purplish color. 4. The peppermint took over 1 hour to dissolve (longer than the lemon juice and vinegar)5. Bubbles and Fizz are present on top of the clorox. 6. Out of all of the solutions I found this one to be most interesting because after 30 minutes only the peppermint skeleton remained (white dissolved red stripes still there). It took over 3 hours for the red skeleton to chip away and dissolve into the solution. --------------Conclusion: I had known a chemical reaction had taken place because of the color change, odor change, and bubbles of gas were being produced.

Clorox (Disinfecting)

For this experiment I poured some clorox into the glass and then dropped the mint in there. As soon as i did that I had to put a plate over the glass because the smell was really strong. 1. As soon as I dropped the peppermint into the clorox it made a sound (like the sound of when you open a can) and it immediately started to fizz2. While the peppermint quickly dissolved bubbles and fizzing were being produced3. Within ten minutes the peppermint quickly dissolved4. At first there was a little clear-red-ish color change but after the peppermint dissolved the color change was no longer visible it turned back to clear liquid5. I could not really tell if there was a smell change just because I did not really take a good sniff at the clorox because it is hazardous and not safe to smell. I immediately threw away the clorox but what I can say is that clorox by it self has a really strong odor. 6. Since I covered the glass with a plate over it i noticed some fogging up on the glass. This is probably because the gas has no where to escape therefore causing the glass to fog. -----------------Conclusion: I knew a a chemical reaction had taken place because of initial color changed and bubbles of gas were being produced. Also my glass was fogged up.

Heat

For this experiment I took a pot and put hot water into it and then let it sit on the gas burner until i saw it boiling. I then dropped the peppermint into the pot. 1. When I first dropped it in it immediately started to meld and created fizz and bubbles.2. I then saw that the red stripes of the peppermint was changing the color of the water from clear-pink-ish & red-ish. 3. Within three minutes the peppermint had completely melted. 4. I then smelled the water and it smelled like peppermint. ----------------Conclusion: I knew a chemical reaction had taken place because of the color change, odor change, it melted due to the boiling water, and bubbles of gas were being produced. ______________________________________________________________________________________Lastly...

I had trouble designing my experiments because I wasn't sure if what I was doing was going to be correct. For instance I wasn't sure if my peppermint idea would work. I thought I should use other food items. After contemplating on what to do for awhile I decided I should go ahead and just try it because I had nothing to loose, I would just gain more knowledge even if it didn't work. When I tried it, I was pleased with my results and wrote down everything I saw. While I was observing I wasn't sure of some observations. For example, with the lemon juice I wasn't sure if the liquid got more dense, if the volume increased, and were those little particles in the lemon juice the leftovers from the peppermint? I then tried to use clues and asked my self why the liquid was separating. I guessed that maybe what I called "sediments" were a solid and that the solid was more dense therefore causing it to float to do the bottom. After the lemon juice experiment I started to understand most of what was happening.

Note: The picture's are all in order from what I did first to last.______________________________________________________________________________________